From mboxrd@z Thu Jan 1 00:00:00 1970 From: Catalin Marinas Subject: [PATCH v7 21/29] arm64: mte: Allow {set,get}_tagged_addr_ctrl() on non-current tasks Date: Wed, 15 Jul 2020 18:08:36 +0100 Message-ID: <20200715170844.30064-22-catalin.marinas@arm.com> References: <20200715170844.30064-1-catalin.marinas@arm.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: Received: from mail.kernel.org ([198.145.29.99]:37810 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726778AbgGORJj (ORCPT ); Wed, 15 Jul 2020 13:09:39 -0400 In-Reply-To: <20200715170844.30064-1-catalin.marinas@arm.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: linux-arm-kernel@lists.infradead.org Cc: linux-mm@kvack.org, linux-arch@vger.kernel.org, Will Deacon , Dave P Martin , Vincenzo Frascino , Szabolcs Nagy , Kevin Brodsky , Andrey Konovalov , Peter Collingbourne , Andrew Morton In preparation for ptrace() access to the prctl() value, allow calling these functions on non-current tasks. Signed-off-by: Catalin Marinas Cc: Will Deacon --- Notes: New in v7. arch/arm64/include/asm/mte.h | 8 ++++---- arch/arm64/include/asm/processor.h | 8 ++++---- arch/arm64/kernel/mte.c | 18 ++++++++++++------ arch/arm64/kernel/process.c | 18 ++++++++++-------- 4 files changed, 30 insertions(+), 22 deletions(-) diff --git a/arch/arm64/include/asm/mte.h b/arch/arm64/include/asm/mte.h index c93047eff9fe..1a919905295b 100644 --- a/arch/arm64/include/asm/mte.h +++ b/arch/arm64/include/asm/mte.h @@ -23,8 +23,8 @@ void mte_copy_page_tags(void *kto, const void *kfrom); void flush_mte_state(void); void mte_thread_switch(struct task_struct *next); void mte_suspend_exit(void); -long set_mte_ctrl(unsigned long arg); -long get_mte_ctrl(void); +long set_mte_ctrl(struct task_struct *task, unsigned long arg); +long get_mte_ctrl(struct task_struct *task); #else @@ -46,11 +46,11 @@ static inline void mte_thread_switch(struct task_struct *next) static inline void mte_suspend_exit(void) { } -static inline long set_mte_ctrl(unsigned long arg) +static inline long set_mte_ctrl(struct task_struct *task, unsigned long arg) { return 0; } -static inline long get_mte_ctrl(void) +static inline long get_mte_ctrl(struct task_struct *task) { return 0; } diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index e1b1c2a6086e..fec204d28fce 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -319,10 +319,10 @@ extern void __init minsigstksz_setup(void); #ifdef CONFIG_ARM64_TAGGED_ADDR_ABI /* PR_{SET,GET}_TAGGED_ADDR_CTRL prctl */ -long set_tagged_addr_ctrl(unsigned long arg); -long get_tagged_addr_ctrl(void); -#define SET_TAGGED_ADDR_CTRL(arg) set_tagged_addr_ctrl(arg) -#define GET_TAGGED_ADDR_CTRL() get_tagged_addr_ctrl() +long set_tagged_addr_ctrl(struct task_struct *task, unsigned long arg); +long get_tagged_addr_ctrl(struct task_struct *task); +#define SET_TAGGED_ADDR_CTRL(arg) set_tagged_addr_ctrl(current, arg) +#define GET_TAGGED_ADDR_CTRL() get_tagged_addr_ctrl(current) #endif /* diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c index 09cf76fc1090..e80c49af74af 100644 --- a/arch/arm64/kernel/mte.c +++ b/arch/arm64/kernel/mte.c @@ -124,9 +124,10 @@ void mte_suspend_exit(void) update_gcr_el1_excl(current->thread.gcr_user_incl); } -long set_mte_ctrl(unsigned long arg) +long set_mte_ctrl(struct task_struct *task, unsigned long arg) { u64 tcf0; + u64 gcr_incl = (arg & PR_MTE_TAG_MASK) >> PR_MTE_TAG_SHIFT; if (!system_supports_mte()) return 0; @@ -145,22 +146,27 @@ long set_mte_ctrl(unsigned long arg) return -EINVAL; } - set_sctlr_el1_tcf0(tcf0); - set_gcr_el1_excl((arg & PR_MTE_TAG_MASK) >> PR_MTE_TAG_SHIFT); + if (task != current) { + task->thread.sctlr_tcf0 = tcf0; + task->thread.gcr_user_incl = gcr_incl; + } else { + set_sctlr_el1_tcf0(tcf0); + set_gcr_el1_excl(gcr_incl); + } return 0; } -long get_mte_ctrl(void) +long get_mte_ctrl(struct task_struct *task) { unsigned long ret; if (!system_supports_mte()) return 0; - ret = current->thread.gcr_user_incl << PR_MTE_TAG_SHIFT; + ret = task->thread.gcr_user_incl << PR_MTE_TAG_SHIFT; - switch (current->thread.sctlr_tcf0) { + switch (task->thread.sctlr_tcf0) { case SCTLR_EL1_TCF0_NONE: return PR_MTE_TCF_NONE; case SCTLR_EL1_TCF0_SYNC: diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index b5c1c975d38e..35090dbd7363 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -608,11 +608,12 @@ void arch_setup_new_exec(void) */ static unsigned int tagged_addr_disabled; -long set_tagged_addr_ctrl(unsigned long arg) +long set_tagged_addr_ctrl(struct task_struct *task, unsigned long arg) { unsigned long valid_mask = PR_TAGGED_ADDR_ENABLE; + struct thread_info *ti = task_thread_info(task); - if (is_compat_task()) + if (is_compat_thread(ti)) return -EINVAL; if (system_supports_mte()) @@ -628,25 +629,26 @@ long set_tagged_addr_ctrl(unsigned long arg) if (arg & PR_TAGGED_ADDR_ENABLE && tagged_addr_disabled) return -EINVAL; - if (set_mte_ctrl(arg) != 0) + if (set_mte_ctrl(task, arg) != 0) return -EINVAL; - update_thread_flag(TIF_TAGGED_ADDR, arg & PR_TAGGED_ADDR_ENABLE); + update_ti_thread_flag(ti, TIF_TAGGED_ADDR, arg & PR_TAGGED_ADDR_ENABLE); return 0; } -long get_tagged_addr_ctrl(void) +long get_tagged_addr_ctrl(struct task_struct *task) { long ret = 0; + struct thread_info *ti = task_thread_info(task); - if (is_compat_task()) + if (is_compat_thread(ti)) return -EINVAL; - if (test_thread_flag(TIF_TAGGED_ADDR)) + if (test_ti_thread_flag(ti, TIF_TAGGED_ADDR)) ret = PR_TAGGED_ADDR_ENABLE; - ret |= get_mte_ctrl(); + ret |= get_mte_ctrl(task); return ret; }